Change speed gear with hydrodynamic clutch



HNs-.JoAcl-nM M. FRsTER ETAL 2,747,430

CHANGE SPEED GEAR WITH HYDRODYNAMIC CLUTCH 2 Sheets-Sheet 1 May 29, 1956 Filed May 25, 1951 Y Ji 1 13a 13 28- g .15 41a J4 21 ZZ ,2 2916 J3 36 10 11 14' fa n l 9 21 9b J Z4 en,

ya l a V11111 7c Jam* E i 16a 8% 7 9 y ,K0 Jk l i 1 41h 1 5, l il, J 3D y 34 /5 7 1m z 1 1h10 zo 18 16 21 27a 4 77 43 L 1f 19 191120 75 11911 119 l1 1,13 1,5 l vf- 1'\ 1 0 7l? 1g 117 J 11g 1;;5 124 7 109119@ J V n 133 Q) fri-ff, 125 1'20 120a v /f//fe/fr/ors FZ@ 2 /a/f-c/oc/bz fo'rfzlef /far/ f7. ///mn/y Il eodor fr. v/fu/fy/rz/c May 29, 1956 HANS-JOACHIM M. FRsTL-:R ETAL 2,747,430M

CHANGE SPEED GEAR WITH HYDRODYNAMIC CLUTCH Filed May 23. 1951 2 Sheets-Sheet 2 United States Patent i CHANGE SPEED GEAR WITH HYDRO- DYNAMIC CLUTCH Hans-Joachim M. Frster and Karl A. Kollmann, Stuttgart-Bad Cannstatt, and Theodor F. Kiimmich, Stuttgart, Germany, assignors to Daimler-Benz Aktiengesellschaft, Stuttgart-Untertnrkhem, Germany Application May 23, 1951, Serial No. 227,846

Claims priority, application Germany May 23, 1950 31 Claims. (Cl. 74-732) The invention relates to a change speed gear with hydrodynamic clutch particularly for motor vehicles.

It is one object of the invention to increase the eiliciency of such a speed gear.

It is another object of the invention to effect a simplification of speed gears which are provided with a hydrodynamic clutch and to eiect a simplification of their operatlon.

It is a further object of the invention to make an easy changing of the gear ratios feasible.

An additional object of the invention is to provide a substantially noiseless gear.

A further object of the invention is to provide an arrangement and development of the gear which is as Space and weight saving as possible.

Further objects of the invention are concerned with an advantageous locking system for parking and providing a suitable vibration absorbing construction of those gear parts which directly transmit the drive.

Further objects, characteristics and details of the invention are to be taken from the following description of three examples of construction in accordance with the sectional views shown in Figures 1, 2 and 3. Figure 4 is a fragmentary view of a jaw clutch.

In Figure 1, number 1 is the driving shaft of the engine, e. g. the engine crankshaft, which is connected with a driving half 3 of a hydrodynamic clutch 2, which is firmly connected with the shaft 1, and drives a driven half 4.

The .driving half 3 of the hydrodynamic clutch 2 is connected with the coupling piece 5 of a disk clutch 6, which is actuated by a hydraulically controlled piston 7 in such a manner that the coupling is etfected by the pressure of the hydraulic iluid, and the uncoupling is effected by the spring 7a. The counter coupling piece 8 of the coupling 6, which serves as a cylinder, is in rm connection with an interior shaft 9, which is for example constructed as a torsion rod with a small diameter, which provides a certain rotary elasticity, and is provided at its junction ends 9a and 9b on a larger diameter with splines or the like. A ball bearing 5a serves for support of the coupling piece 5 on the hub 8a of the counter coupling piece 8, which in turn is supported by a ball bearing 8b in a hub 10a, which is rmly connected with the driven half 4 of the hydrodynamic clutch. 'Ihe hub 19a is coupled for rotation with a hollow shaft 10. The latter reaches into the chamber 13a of the substantially tripartite change speed gear, which chamber is limited by the two bearings 11 and 12, and carries on its end within the chamber the gear wheel 14 of the constantly meshed gear transmission, which consists of the gear wheels 14 and 15. The gear wheel 15 is rmly arranged on a jackshaft 16. On the latter the gear wheels 17 and 18 are supported in a loosely rotatable manner and the gear wheels can be coupled with the shaft by the disk clutches 19 and 20. The last mentioned clutches are constructed in the same manner as the clutch 6 and have suitably equal diameter measurements with the latter, so that the individual parts of the clutches can be Y C)2,747,430 Patented May 29, 19576l exchanged with each other. Hydraulically operated pistons 19a, 20a engage the respective couplings, when pressure is applied on the right side of the piston 19a or on the left side of the piston 20a, while the release is carried out by springs 19b, 20h. The rmly attached outside clutch plate supporter 16a serves as a cylinder.

The gear wheels 17 and 1S are permanently in gear with the gear wheels 21 and 22 respectively, which are coupled together by the hollow main gear shaft 23, which is rmly coupled for rotation on one hand with the interior shaft 9, and on the other hand with the driven shaft 24.

The jackshaft 16, which is supported in the gear casing 13 by means of the two bearings 25 and 26, is extended beyond the end bearing 26 and carries a gear wheel 27 on its extended end in a self-supporting manner. Said gear wheel 27 meshes with a gear wheel 2S, which is supported in a loosely turnable manner on the driven shaft 24. The latter gear wheel contains a freewheel device 29, the interior ring of which comprises a jaw clutch piece 30 with the jaws 31, which can be coupled with the jaws 32 of a counter coupling piece 33. The latter constitutes a hydraulically operated piston, which is coupled for rotation by jaws 33a with its cylinder, which serves simultaneously as a gear wheel 34 for the reverse gear and is slidable in longitudinal direction against the effect of the spring 33b. The reverse gear may be constituted by a pair of gear wheels 27a and 34a, which are arranged on an auxiliary shaft or reverse shaft 3412, the gear 27a is for example in permanent mesh with the gear wheel 27, while the other gear 34a, which may coact with 34, can be coupled with this gear 34 by longitudinal displacement of a gearshift sleeve.

The gear wheel 34 carries also a jaw rim 35, into which a parking latch 36 engages by means of its jaw 36a and thereby locks against turning the gear wheel 34 and the driven shaft 24, which is firmly connected with it.

The freewheel device 29 is constructed in such a manner that when the gear wheel 2S is driven in forward direction it takes along the jaw member 30 and thereby, when jaws 31, 32 are engaged, drives the vehicle through the jaw member 33 and the driven shaft 24. In forward direction of rotation of the jaw member 33 relative to the gear 28, the gear wheel 2S is uncoupled from the driven shaft 24. The jaws 31 and 32 are, as shown in gure 4, suitably beveled both at their faces 37 and 38 and at one tlank 39, 4t?. The rst has the purpose to facilitate the engaging of the coupling, as soon as the hydraulic pressure acts on the piston 33 and thereby seeks to engage the jaws 32 into the jaws 31. Through the beveling of the teeth surfaces 39, 45 the release of the coupling is facilitated when the coupling is under load.

For control of the clutches 6, 19, 20 and the coupling 33 provision is made for an oil-pressure system, vwhich is not shown in detail in the drawing, and which directs the liquid to the operating pistons, for example through the hollow shafts, as it is indicated for the operating pistons 19a, Ztla by the conduits 19e, 20c. The coupling piston 7 receives oil through a groove 7b in the hollow shaft.10,

which is supplied at the front, from a connection boring 7c. In order that the system can be kept under pressure both at standing vehicle, but running engine, and at running vehicle, but standing engine, provision is made on one hand for a primary gear pump 41, which is driven by the cover member 42, and which is connected with the driving half 3 of the hydrodynamic clutch and consistsV of an annular gear 41a and a spur gear 41b, which runsA in the latter, and on the other hand a secondary gear pump 43, which receives its drive from a gear wheel 44, which is for example driven by the gear wheel 18, which gear wheel 44 is permanently coupled with the driven shaft of the transmission and serves forV example also for the drive of the tachometer.

The transmission is constructed as a four speed gear. 'I'he pair of gear wheels 14, 15, which is in permanent connection with the driven half 4 of the hydrodynamic clutch through the hollow shaft and thereby provides atransmission of the drive in the first three gear ratios through the hydrodynamic clutch, is utilized'for the rst three gear ratios. The first gear ratio isY achieved through the gear Wheels 27, 28, the second gear ratio bythe gear wheels`17, 21 and the third gear ratio by the gear wheels 18,-22. The constantly meshed gears 14, as Well as the gear pairs27, 27 for the rst gear ratio, and 18, 22 furthe third gear .ratio are hereby arranged directly adjacent to :the kbearings 11, 12, and the bearings 25, 26, whereby a particularly noiseless transmission, particularly in the third gear ratio, results. The .gear'wheels17, 21 for the second gear ratio arearranged `directly adjacent 'to the .constantly engaged gearsV 14 and 15, which assures a noiseless gearing' as well. As a result of theV outboard varrangement of the gear wheel 27 the distance of the bearings 25 and 26 can be kept relatively short in spite of the interposng of the couplings 19 and '20.

In the position illustrated the gear'is in neutral. Through displacement ofthe piston 33 to the left, the first gear Y ratio is .-effective, so that the drive is transmitted to the driven shaft 24 through the hydrodynamic clutch, the

Y the coupling 33.

VVAs soon as one of the two other clutches, for example the clutch 19 for the second gear, is engaged, whereby the drive lis transmitted from the jackshaft k16 through the pairv of gear wheels 17, 21 to the shafts 23, 24, the first gear is automatically released by overrunning of the freewheel device 29, without necessitating the release of jaws 31, 32. When the clutch 19 is released, theY rst gear isY automatically shifted Vin again.

For achieving the thirdV gear ratio the clutch 2t?V is engaged and the clutch 19 released, whereby thedrive is effected through'the pair of gear wheels 1S, 22. VIn all these gears the drive is effected through the hydrodynamic clutch, as a result of which an easy shifting and smooth starting is assured.

, IFor'achievemcnt of a direct drive the clutch 6 is'engaged by placing the piston'7 under pressure and the coupling 20 is released. Hereby the engine shaft 1V and the driving half 3 of the hydrodynamic clutch is connected directly with thefinterior shaft 9 and thereby through the shaft 123 with thedriven shaft 24. The hydrodynamic 'I 'clutch'is thereby ineifective since the clutch 6 acts as a bridging coupling. VThrough this a high efficiency is guaranteed Vh1 direct drive. Y

AWhen the reverse gear is engaged by connecting the two gear wheels 27 and 34 through the reverse gear. shaft the jaw connectionY 31, 32 is disengaged. In all other gears the piston 33 is suitably under pressure, so that the jaws 31, 32 are consequently in gear. Hereby the vehicle is :automatically secured against backward rolling or an upgrade, as long as one of the upper gears is engaged, sinceras aresult Aof the double transmission of theY drive through'the respective second and third gears as well Y as through the iirstgear, which becomes simultaneously effective atbackward'direction of rotation through the frcewh'eel coupling 29, the drive is locked. This blocky ingY is terminated when no disk clutch has oil pressure; If fol-:parking a rolling ofthe vehicle'pis to be prevented, the parkingrlatch 36 Ycan be brought into mesh with theY gear rim V35; I Y

Infthelforms shown-in Figures Zand 3 the parts which correspondrin 'their effect Yto those in Figure 1 are provided with the "same referenceV numeral exceptthat in eai caseit :is increased by OOfan'cl 200, respectively.

The form of construction in accordance with Figure 2 is mainly distinguished from that in accordance with Figure 1 through the fact that the constantly meshed gears 114 and Y115 are arranged at the rear end of the transmission and connect the jackshaft 116 with the driven shaft 124. The hollow shaft 110, which is connected with the driven half 104 of the hydrodynamic clutch'is extended tothe rear end .of the transmission, while the interior shaft 109 is directly coupled with the driven shaft 124.

To achieve the rst gear ratio provision is made for a yjaW coupling piece 133, through which the. gear wheel 128 can be connected, through the freewheel coupling 129 with the jackshaft 116 in one direction of rotation. The drive in the first gear is then eiected through the hydrodynamic clutch'102, the hollow shaft 110, the pair Y jackshaft 116 and the first gear 117 is coupled with the ,Y

main shaft throughthe disk clutch 119. For achieving the third gear ratio the coupling 120, which couples the gear wheel 122 with the jackshaft, is engaged andthe coupling 119 released, whereby the transmission is effected through the pair'of gear Vwheels 118, 122. Y

In the fourth or direct drive only the coupling 106 is shiftedV in, which Vprovides a direct drive transmission under bridging of theV hydrodynamic clutch from the engine shaft 101 through the interior shaft 109 to the driven'shaft 124. Y

The reverse gear is for Vexample .effected through -a gear Ywheel 134, which can be brought, in drive connection Vwith a gear wheel, which is arranged on the main shaft, for example the gear wheel 115, through a reverse gear shaft (not shown in the drawing). A parkinglock canfor example be provided for at the front end of the jackshaftat 135, where forrexample also the drive of the' secondary 'pump is effected at 143. The primary pump is indicated at 141.

As is to be seen, in this case the gear wheels of the second gear are arranged outside the gear chamber, which is limited by the bearings 111, 112 respectively 125, 126, i. e. the gear wheel 121 is mounted outboard on the jacks haft116. 1

The coupling 119 for the second gear is located outside this gear chamber.V In contrast with the form of construction in accordance with Figure l the gear Wheels of the rst and of the reverse gear including the freewheel device 129 areY arranged within the gear chamber. A11 additional bearing Serves in connection with thelbear- 113 and thereby to guarantee quiet running of the gears.

The oilsupply to the couplings 106, 119 .and'120 -is for example again eifected through borings orrconduits in the shafts.Y Thus for conducting ofthe oil to the cou- Y pling piston v117911, a conduit Y1:19ais provided in the hol low shaft 111),.through the outside annular groove to which the oil is conducted Vfrom `11/9a". Theoil is sup'-VY plied to the coupling piston-12651 from pipe 12nd through' the boring'120c vin the `.jackshaft'1'16.` The :conduction to the coupling piston 167 can be effected'th'roughltheinterior shaft 1119. Y

' Y VAs is to be seen, particularly the shafts 9 and, 1l't9frazey developed as torsional rods, whereby nonuniformties inV the direct drive are received elastically l.whilel the hydro which a'et *throughithe hydrodynamic clutchr-.the .vibra-4 tions and shocks are received by the hydrodynamic clutch.

The construction in accordance with Figure 2 has, above all, the advantage that as a result of arrangement 6 Y is connected with the gear wheel 221 by means of a hollow shaft 252, the other coupling half 253 of the coupling 219 is arranged on the interior shaft 209. The gear Wheels 214 of the constantly meshed gear pair 214, 215

of the constantly meshed gears at the driven side of the 5 and .221 for the rst gear ratio are supported between transmission the couplings for the individual gear shifts bearlrlgS 211 and 245- have to transmit smaller torsional moments. The cou- In the first through third gear ratios as well as in the plings are arranged in such a manner that at the given reverse gear the drive transmission is carried out through transmission ratios they have to transmit the smallest posthe hydrodynamic clutch 202, the driven part 204 of sible moment 10 which drives through the hollow shaft 210 in constant 'Ihe form of construction shown in Fig. 3 distinguishes CODDeCOn With the Pair 0f gear Wheels 214, 215 and mainly from the two forms of construction as described therethrehgh With the aekShaf 216 The gear Wheels above therein that the pairs of gear wheels for the gear 228 fOr the rS gear, 221 fOr the Second gear and 222 fOr transmissions are located between the shifting couplings, the third gear rotate together. For electingv the rst i. e. the latter are arranged at the ends of the gear chamgear ratio the coupling 233 is coupled with the jaws 231. ber respectively outside of same. 'Ihe constantly meshed When a higher gear is engaged, the gear wheel 228 is gears 214, 215 are located, as in the construction in acthereby overrun and the rst gear ratio becomes ineifeccordance with Figure l, at the front end of the gear. tive. If for electing the second gear ratio the coupling Directly adjacent the Pair 0f gear Wheels 217, 221 f01 219 is engaged, the latter connects the gear wheel 221 IOWS 1he Second gear Pair 217 and 221, the hrSt 0f Which 20 with the interior shaft 209, so that the drive is trans- S hrh'dY Connected With the gear Wheel 215 and the J'a'ck mitted from the hydrodynamic clutch through the gear Shaft 216, which is develoPed as a hollow Shaff- Behmd wheels 214, 21s, 217, 221 and through Clutch 219 to the the gears 217 and 221 are gear wheels 227 and 228 (for interior shaft 209. In order to make a connection from the irst gear ratio) with the freewheel device 229. Then 25 shaft 209 to the driven shaft 224 feasible, the coupling follow .the feverse, gear Whee,1s 24,6 and 234 Whlch can 233 must therefore also be engaged to effect the second be brought into drive connection with each other through gear ratio. a gear wheel 247, which is indicated by adotted line, and For shifting to the third gear ratio the Clutch 220 is nally the gear Wheels 218 222 for the dimi gear fano' engaged. The drive is in this case effected from the .The gear 222 1S engage@ by the. cmip 1mg 220 the cou' 30 hydrodynamic clutch through the gear wheels 214, 2115, pling member 248 of which, which is rmly connected 218 222 d. t1 t th d h ft 224 Th third with the driven shaft 224, carries a gear rim 235. In this ec y o e .nven s a e gear gear rim the jaw of an axially adjustable sleeve 236 for does -therefore not require the coupling' 233, so' that on parking can engage which is Supported in the casing pref occasion the latter can also be released in the third gear.- erebly en an axle member 249, which is firmly xed in l In the direct drive the driving half 203 o f the hydrodythe casing and Serves for 'Support of the jackshaft 216 35 namic clutch is again directly connected with the interior For direct coupling of the engine shaft 201 relative Shaft 209 by the ehlteh 206, Wherehy the Connection O to the driven half 204 of the hydrodynamic clutch 202 the driven shaft 224 is again effected by the jaw clutch a disk clutch 206 is provided, the one coupling member of 233. which is connected to the clutch half 203 of the hydro- 40 The drive of the primary pump is again effected by a dynamic coupling and the other coupling member of casing-shaped part 242, which is connected with the drivwhicli is firmly connected with the shaft 209. ing half 203 of the hydrodynamic clutch, for examplev VThe Shaft 209 Carries 0n its rear end by means 0f the by means of a spiral gearing 241, while the secondary oil freewheel device 229 the already mentioned gear wheel pump is for example driven by a gear Wheel 244 of the 228 for the rst gear and can be directly coupled by means driven Shaft 224 0f the laWS 231 ihren@ the aW Coupling member 233 v In the three examples of construction illustrated the With the driven Shaft 234 The Same Coupling member shifting clutch 6, 106 or 206 is arranged forv providing 233 serves for the purpose to couple the gear wheel 234 a direct gear within the interior circumference of the withthe driven shaft -224 by means of the jaws 250. hydrodynamicclutch, so that the shifting coupling does For effecting the second gear ratio provision is made not increase the over-all length of the transmission. fora disk clutch 219, which is arranged within a casing- In order to facilitate an understanding of the operationv shaped part of the hollow shaft 210, which connects the of the forms of construction shown as illustrative of the driven half 204 of the hydrodynamic coupling with the invention, reference may be had to the following tabugear wheel 214 of the constantly meshed gears 214, 215. lations showing the setting of the several clutches an While the one coupling member 251 of the coupling 219 couplings to eiect the dijerent drive ratios: i

Form of Figure 1 clutch e clutch i9 clutch 2o Cgllfzng Pggrugistld Neutral Disengaged. Disengaged.. Disengaged.. Disengagedt. None. 1st gear dn dn do Engaged. 14, 15, 27, 28. 2nd gear do Engaged..-- --.do OptionaL 3rd gear do Disengaged.. Engaged do Direct Engaged. do Disengaged.- Optiona1 Form of Figure 2 clutch ioe clutch 119 oiutch 120 coupling 133 Pgrlgllstd Neutral Disengaged- Disengaged. Disengaged.. Disengaged.. None. 1st gear dn do dn Fngfmpd 127, 128, 114, 115. 2nd gear do Engaged do Optional 117, 121, 114, 115. 3rd gear dn Disengaged.. Engaged do 118, 122, 114, 115. Direct Engaged --.-do Disengaged.. Disengaged. None.

' third and second shaft to4 'the first shaft.

f Form of Einmal? I f i Bower transmitted Clutch 205 Clutch 2179 Clutch 220 Coupl1ng233 throughgeark Disengaged.. Disengaged.. Disengaged.. Disenga'ged" None. dn Y k dn dn VEngages 2.3L 214, 215,227, 228. do Engaged do do 214, 215, 217,` 221. do Disengaged Fkln'gagedrr...V 0ptional. 214, 215, 218, 222.

Engaged do Disengagedf `Engaged. None.

Itvvill be noted that the construction shown andldescribed will serve admirably Vto accomplish the 'objects `stated above. It is to be understood, however, that the construction disclosed above is intendedmerely 'as .illustrative f1the invention and not Vas limiting as various modications therein may be made without, departing from the invention as vdefined by a proper interpretation of the claims-which follow. t

Y We claim:

l. Change speed gear comprising va driving member,

a hydrodynamic clutch with a driving clutch part which isconne'cted with the diiving member, and afdriven clutch Y gearV member.

'2. Change speed gear comprising a driving member,

i afhydrodynamic clutch with a driving clutch part which i'siconnected with the driving member, anda driven clutch part, an interior shaft, a second clutch for coupling the driving Yclutch part of the hydrodynamic clutch with the interior shaft, a hollow shaft surrounding said'interior shaft lconnected with-the driven-part of the hydrodynamic clutch, a driven gear member, means for directly connecting the driven part of thefirst clutch with this gear member, a jackshafvt, a pair of gear `wheels for'conn'ecting the hollow shaft with the jackshaft and with the driven gearmember and at least one additional clutch'arranged on=the jackshaftfor coupling one of the gear wheels lwith the jackshaft. Y y Y 3. `Change speed gear in'accordance with'claim 1, wherein the clutch'for connecting the driving clutch part of the hydrodynamic clutch with the interior shaftwis Y' arranged ,radially withinV the Vvane ring vof the'hydropart which is connected With the driving member, anda driven clutch part, an interior shaft which is rotatable with the one clutch part, a "shaft which coaxially surrounds the first shaft and isrotatable'withthe other clutch part, amain gear shaft 'coaxialfwith the aferenr'entiorned shafts with means yfor direct coupling with thejinterior;

shaft, a jackshaft, atleast three pairs' of gear wheels for connecting the jackshaft with `the surroundingshaft'and the main gear shaft, at least two disk clutches for cou' pling of two pairs `of gear wheels with :oneof the pertinent shafts, two bearings for support of the 'jackshaftin the casing, one bearingreach for'support of the vsurrounding shaft and of the main gear 'shaft in the casing,`whereby the gear'wheels are arranged close to the bearings and the clutches are arranged between the gear Wheels, and a further clutch for coupling'the inte'rior'shaft'with that part of the hydrodynamic clutchwhich'is Vrotatablewith it in immediate .vicinityof the said hydrodynamic clutch.A

7. AChange speed gear comprisingra gear, casing, 'a dnving member, a lhydrodynamicclutchewith a driving clutch part'which is connectedwith Athe driving member, and Va driven clutch part, an interior shaft which" is rotatable Ya jackshaft, at least three pairs of vgear wheelsffor con-t nection Aof the kjackshaftlwiththe surrounding vshaft and the main `gear shaft, 4at least two disk clutchesifor vcouconnected with the driving member, and `=ad1'iven'clutch Y part, affirst interior shaft, Va second shaft whichV encloses the interior shaft concentrically,tand a third shaft which. encloses the second shaft concentrically, a second clutch for coupling the first shaft with the drivingelutch part of vrtheA.hycl-rodynamie clutch, means vfor connecting 'the third shaft with the driven clutch .part ofthe hydro-V dynamic clutch', a gear wheel on ythe second shaft, a gear wheel'on `the third shaft, a jackshaft, one gear wheleac'h on the jacksha'ft in mesh with one each 'of lthe aforementionedgeaij wheels, Vadriven gear shaft, at leastonepair of gearwheels connecting Athe jacksha'ft Awith the 'driven Y gear shaft, Vand a third clutch for direct coupling of ,the irst'interior shaft With the driven gear shaft.

5.Y Change speed gear in accordance with claimA 4 wherein 'the 4seconc'l'shaft is connected Athrough `t`he `first mentioned gear wheels 'with the third fshaft, infcombina- -r Y tion with a vfourth clutch for Ycoupling the .secondshaftl Nmeans-on--the shift sleeve as Vwell as on the rotating gear with the firstv shaft so `that -a drivenfrom the ,driven par-t Y pling loftwo pairs of gear wheels 'with one of the'pertinent shafts, two bearings for vsupport of the jackshaft in the casing, one bearing each-for support lofthe surrounding shaft and of the main Vgear shaft in the casing,-whereb'y two of the pairs lof gear wheels are arranged 'on vboth sides of the -on'e'pair of lbea-rings on'the pertinent shafts and vthe other pair of Ygear wheels'is 4arranged at the other Y bearings-of the pertinent shafts, theone disk clutch between the bearings and "thegear wheels rwhich are arranged between vthese, and the other disk clutches outside the bearingsfandadjacentto the gear wheels, whiclrareY arrangedoutside the .gear wheels, and a fur-ther clutchY Y for coupling the interior :shaftvwith that part-:oflthe hydrodynamic lclutch `which may rotate :with it, 1in immediate vicinity of said hydrodynamic clutch. Y

'8. Change f speedl gearlin accordance Aavifth claim L6 wherein Vall disk clutchesrhave equal measurementsV so that they are exchangeable With each other.

9. v'Chan'gesp'eed gear comprising a casing, a gear shaft, a non-rotatable gear shaft supporting rod parallel toY said first mentioned shaft, a gear member rotating with the first gear shaft, a shift sleeve arranged slidably and non- ,rotatably ,onethe parallel gear shaft supporting rod, and

Tmember adapted to couple the two parts with each other and to therebyrlock the first the casing.V

10. A speed'change transmission comprising a driving member, a driven shaft, means including a disengageable friction clutch adapted to establish a direct power-trans- `,.xrlitting-connect-ion between saiddriving member Yand said Y :driven shaft,a;.second shaft, a plurality of gearings of AFdifferentratio'saofl transmission mounted on said shaftsy Y ac'lilt saidggearings being adapted to be optionally y'rendered ine'ect'ive or effective to establish a power -transmitting Yconnection between said second shaft'and mentioned shaft relative to said driven shaft, and means including a hydrodynamic clutch adapted to establish a driving connection between said driving member and said second shaft.

ll. A speed change transmission comprising a driving member, a driven shaft, means including a disengageable friction clutch adapted to establish a first power-transmitting connection between said driving member and said driven shaft, a second Shaft, a plurality of pairs of meshing gears mounted on said second shaft and on said driven shaft, said pairs having different ratios of transmission, one gear of each pair being fixed to its shaft, a disengageable clutch coordinated to the other gear of each pair and its associated shaft and adapted when engaged to establish a second power-transmitting connection between said second shaft and said driven shaft, and means including a hydrodynamic clutch adapted to extend said second power-transmitting connection from said second shaft to said driving member.

12. Speed change transmission as claimed in claim l1 in which said iirst power-transmitting connection is a direct connection of a 1:1 ratio, whereas said second power-transmitting connection is a speed-reducing connection causing said driven shaft to run at a lower rate of speed than said driving member.

13. In a speed change transmission for motor vehicles, the combination comprising a driving member, a driven shaft adapted to be geared to the wheels of the vehicle, a second shaft, a plurality of pairs of reducing gears of various ratios of transmission mounted on said shafts and adapted to establish a driving connection therebetween, said pairs including one low speed pair having the highest ratio of transmission of said pairs, a hydrodynamic clutch composed of two sections, one of said clutch sections being connected to said driving member and the other one of said sections being geared to said second shaft, a free-wheeling clutch being included in the train of motion-transmitting elements constituted by said second shaft, by said low speed pair and by said driven shaft, said free-wheeling clutch being mounted to enable said driven shaft to overtake the associated gear of said low speed pair when driven by one of the other pairs of gears, and a clutch adapted to establish a direct driving connection between said driving member and said driven shaft.

14. Speed change transmission as claimed in claim in which one of said plurality of gearings is connected to one of said shafts by a free-wheeling clutch.

15. A speed change transmission comprising the cornbination set forth in claim 10 combined with a detent member mounted in the casing of the transmission and adapted to cooperate with said driven shaft for the purpose of blocking same, and with means for disabling and enabling said member to cooperate with said driven shaft.

16. In a speed change transmission, the combinationA comprising a shaft, a rst gear, a second gear and a rotary member mounted on said shaft for relative rotation, freewheeling clutch means permanently interposed between said first gear and said rotary member, and disengageable tooth-clutch means for positively clutching said rotary member and said second gear.

17. In a speed change transmission, the combination claimed in claim 16 in which the teeth of said toothclutch means have end faces positioned at an acute angle to a plane extending at right angles to said shaft, one side face of each tooth extending at an acute angle to the axis of said shaft.

18. A speed change transmission for a motor vehicle comprising a driven shaft adapted to be geared to the wheels of the vehicle, three gears mounted coaxially thereto, means for connecting said three gears to said driven shaft, a secondary shaft, three gears mounted on said secondary shaft and meshing with said first mentioned gears, multi-disk friction clutches for connecting and disconnecting at least two of said last mentioned gears to and from said secondary shaft, a gear casing having partitions, anti-friction bearings in said partitions supporting said shafts,`s'aid Vgears being located between said anti-friction bearings and said multi-disk friction clutches, a member adapted to be connected to the engine of the vehicle, Va train of motion-transmitting elements connecting said member to said secondary shaft and including a hydrodynamic clutch, and a disengageable clutch adapted to connect said driving member to said driven shaft for common rotation.

19. In a speed change transmission, the combination set forth in claim 13 in which a bearing is provided for said second shaft, one end of the latter projecting therefrom, said low speed pair including a gear mounted on said end of said second shaft.` I

20. In a speed change transmission for motor vehicles, the combination comprising a driving member adapted to be connected to an engine, a driven shaft adaptedvto be geared to the wheels of the vehicle, a hydrodynamic clutch composed of a driving section connected to said driving member, and of a driven section, both sections constituting an annular chamber adapted to contain a liquid, a reduction gearing, means adapted to render said reduction gearing ineffective or elective to connect said driven section of the hydrodynamic clutch to said driven shaft, a clutch adapted to establish a direct power-transmitting connection between said driving member and said driven shaft, fluid-controlled means to disable said reduction gearing, and huid-controlled means to engage said last mentioned clutch when said reduction gearing is ineffective.

21. In a speed change transmission for motor vehicles, the combination comprising a hydrodynamic clutch composed of a driving section adapted to be connected to the engine of said vehicle and of a driven section, both sections constituting an annular chamber adapted to contain a liquid and having vanes in said chamber, a hollow shaft connected to said driven section of said hydrodynamic clutch, a driven shaft adapted to be geared to the wheels of the vehicle, said shafts and said sections being mounted in coaxial relationship, a reduction gearing, means rendering said reduction gearing inelfective or effective to connect said hollow shaft with said driven shaft, and a train of motion-transmitting elements connecting said driving section and said driven shaft and including a disengageable clutch and an inner shaft mounted within said hollow shaft.

22. A speed change transmission as claimed in claim 10 in which said driving member, said driven shaft, said friction clutch, and said hydrodynamic clutch are mounted in coaxial relationship.

23. A speed change transmission as claimed in claim 21 in which said friction clutch is mounted within said hydrodynamic clutch and in coaxial relationship thereto and to said driven shaft.

24. Change speed gear in accordance with claim 10 comprising a transmission shaft formed by a torsionally elastic rod which is included in said direct power-transmitting connection.

25. Change speed gear in accordance with claim 1 wherein the interior shaft is a torsionally elastic shaft of small diameter.

26. Change speed gear in accordance with claim I wherein the interior shaft is a torsionally elastic shaft of small diameter and the second clutch and the third clutch are hydraulically operated disk clutches.

27. Change speed gear in accordance with claim 10 comprising furthermore a transmission shaft which is a torsionally elastic rod included in said direct powertransmitting connection which bypasses the hydrodynamic clutch, and friction clutches for rendering said gearings effective or ineffective.

28. Change speed gear in accordance with claim 10 comprising a transmission shaft formed by a torsionally elastic rod in said direct power-transmitting connection which bypasses the hydrodynamic clutch, said rod having a small diameter over most of its length and having 1 1 enlarged splined ends for couplings'aidtransmssion shaft with vsaid drivingmeinber on one hand and with .said driven shaft'on the other hand.

29. Change speed gear in accordance with c1aim`-16 wherein the :second gear wheel is formed Vto provide a cylinder and said disengageabietooth-clutch means include a piston fof actuation.

30. Change speed gear in accordance with 4claim V16 comprising alsofa ,casing,t1neans;for .spliningr said second gear to said shaft, and meansfor locking the second gear and thereby also theshaft relative to the casing.

f 31. Change speed gear comprising a casing, a driving gear shaft, a driven transmissonshaft, a jackshaft, two bearingsV forsupport of the jackshatt'in the easing, lone bearing Vfor each of the twovrst-mentioned shafts, at leastronepair of lgears for connecting the jaekshaft with the driving shaft andgatleasttwo pairs of gears for connectng the jackshaft with the driven transmission shaft,

gear wheel arranged'on `the 'drivenshaf and means forY References Citedin the le ofthis patent UNrrEDfsTATEs 'PATENTS Re. ,22,967 YNutt et al. Ian. 27, 1948 2,226,802 'Black Dec. 31, 1940 `2,277,214 Dodge Mar. `24, 1942 2,449,608 ,Le May .,Sept. 21, 1948 2,449,964 Banker, ..`Sept. 21, 1948 2,453,794A Iavelli NOV. 16, 1948 2,507,999 Schjolin May 16, 1950 '2,534,134 Kirkpatrick Dec. 12, 1950 2,567,446 YPolomski Sept. 11, 1951 2,591,342 Dodge Apr. Y1, 1952 2,620,684 McFarland Dec. 9, 1952 2,627,189 McFarland Feb. 3,'1953' FOREIGN k,PATENTS France` Y.. Y Apr. 5, A1,948

' 938,552 Y Y OTHER REFERENCES Packard Servicemans Training Book 'on Ultramatic Dn've (recd June 27, 1949). 

